The presence of arsenic in ground and surface water has prompted considerable research efforts[unreadable] toward understanding the health impact of arsenic ingestion, its environmental fate and transport, and[unreadable] its removal from potable water. Arsenic is considered a human carcinogen and drinking arseniccontaminated[unreadable] water is linked to increased risk of diabetes, cardiovascular problems, hormonal[unreadable] disruption, cancer, DMA damage, and vascular diseases. Arsenic is often associated with metal[unreadable] oxides and humic materials in drinking water supplies. The working hypothesis for this research[unreadable] proposal is that the interactions, bonding and reactivity of arsenic on metal oxides play key roles in the[unreadable] bioavailability, toxicity, and effective remediation of arsenic. A fundamental knowledge of arsenic[unreadable] redox kinetics and adsorption properties is critical for understanding the health risks associated with[unreadable] the bioavailability of arsenic, the fate and transport of arsenic in the environment and for the[unreadable] optimization of treatment processes for the removal of arsenic species from drinking water.[unreadable] The primary goal of the proposed study is to develop a fundamental understanding of the adsorption[unreadable] and oxidation of toxic arsenic on metal oxide surfaces using microscopic imaging, spectroscopy, and[unreadable] molecular manipulation techniques. Titanium and tin oxides will be used as the model metal oxides[unreadable] because of their potential applicability for the remediation of arsenic. The role of the metal oxide[unreadable] surface, and the kinetic and mechanistic parameters of titanium dioxide photocatalytic and tin oxide[unreadable] electrochemical remediation (oxidation and adsorption) of arsenic species will be established. The[unreadable] parameters established from the proposed studies are critical to the development of effective[unreadable] technologies for the treatment of arsenic contaminated waters. The long-term goal of the proposed[unreadable] research is to establish the mechanisms that govern the adsorption, reactions and release of arsenic[unreadable] from metal oxide surfaces. We expect the data generated from these studies can be input into[unreadable] environmental risk models that evaluate the probability of the health effects of ingestion of arsenic[unreadable] contaminated water by animals and humans.